president obama is calling the test a highly provacative act. he condemned it in a statement overnight saying north korea's nuclear weapons and ballistic missile program constitutes a threat to u.s. national security and to international peace and security. north korea has been warning for weeks that it was about to test its nuclear arsenal. on tuesday morning, it exploded a bomb in a facility one kilometer underground near the same location of its nuclear test in 2006 and 2009. >> there is concern that they could come up with a delivery system for their nuclear weapons. >> reporter: last week the u.s. and south korean navies launched military drills in the region as a show of force. north korea's test demonstrates a significant split from its main patron, china. recently beijing warned leader kim jong-un against any weapons tests. >> they've said publicly that there would be real consequences for north korea. what those consequences are we have to see, but i suspect it's going to be more than an angry lettered. >> reporter: china is one of the